Isolation Barrier

ABSTRACT

An apparatus and method for securing a tubular within another tubular or borehole, creating a seal across an annulus in a well bore, and centralising or anchoring tubing within a wellbore. A sleeve is arranged on a tubular body to create a chamber therebetween. A port provides fluid access through the body to the chamber. A support frame of bow springs on mounts is located within the chamber. When fluid is introduced into the chamber the sleeve is morphed to secure it to a well bore wall, an end of the sleeve will move along the body and compress the frame and bow springs. The compressed springs support the sleeve to maintain a seal between the sleeve and well bore wall to form an isolation barrier.

The present invention relates to an apparatus and method for securing a tubular within another tubular or borehole, creating a seal across an annulus in a well bore, and centralising or anchoring tubing within a wellbore. In particular, though not exclusively, the invention relates to morphing a sleeve to secure it to a well bore wall by the use of fluid pressure and a frame of bow springs, the bow springs being used in supporting the sleeve to maintain a seal between the sleeve and well bore wall to form an isolation barrier.

In the exploration and production of oil and gas wells, packers are typically used to isolate one section of a downhole annulus from another section of the downhole annulus. The annulus may be between tubular members, such as a liner, mandrel, production tubing and casing or between a tubular member, typically casing, and the wall of an open borehole. These packers are carried into the well on tubing and at the desired location, elastomeric seals are urged radially outwards or elastomeric bladders are inflated to cross the annulus and create a seal with the outer generally cylindrical structure i.e. another tubular member or the borehole wall. These elastomers have disadvantages, particularly when chemical injection techniques are used.

As a result, metal seals have been developed, where a tubular metal member is run in the well and at the desired location, an expander tool is run through the member. The expander tool typically has a forward cone with a body whose diameter is sized to the generally cylindrical structure so that the metal member is expanded to contact and seal against the cylindrical structure. These so-called expanded sleeves have an internal surface which, when expanded, is cylindrical and matches the profile of the expander tool. These sleeves work well in creating an annular seal between tubular members but can have problems in sealing against the irregular surface of an open borehole.

The present applicants have developed a technology where a metal sleeve is forced radially outwardly by the use of fluid pressure acting directly on the sleeve. Sufficient hydraulic fluid pressure is applied to move the sleeve radially outwards and cause the sleeve to morph itself onto the generally cylindrical structure. The sleeve undergoes plastic deformation and, if morphed to a generally cylindrical metal structure, the metal structure will undergo elastic deformation to expand by a small percentage as contact is made. When the pressure is released the metal structure returns to its original dimensions and will create a seal against the plastically deformed sleeve. During the morphing process, both the inner and outer surfaces of the sleeve will take up the shape of the surface of the wall of the cylindrical structure. This morphed isolation barrier is therefore ideally suited for creating a seal against an irregular borehole wall.

Such a morphed isolation barrier is disclosed in U.S. Pat. No. 7,306,033, which is incorporated herein by reference. An application of the morphed isolation barrier for FRAC operations is disclosed in US2012/0125619, which is incorporated herein by reference. Typically, the sleeve is mounted around a supporting tubular body, being sealed at each end of the sleeve to create a chamber between the inner surface of the sleeve and the outer surface of the body. A port is arranged through the body so that fluid can be pumped into the chamber from the throughbore of the body.

In use, the pressure of fluid in the throughbore is increased sufficiently to enter the chamber and force the sleeve radially outwardly to morph to the generally cylindrical structure. Sufficient pressure has been applied when there is no return of fluid up the annulus which verifies that a seal has been achieved. Though the sleeve has been plastically deformed and will therefore hold its new shape, if a sufficient pressure differential is created across the sleeve wall, there is a possibility that collapse can occur and the seal may be lost.

In GB1314692.3 to the present applicant's a swellable material is located within the chamber. The material swells on contact with fluid entering the chamber to support the morphed sleeve member against the surface of the wall of the cylindrical structure against which the seal is required. While this advantageously creates a support to the morphed sleeve, the quantity of swellable material must be carefully controlled to ensure that the sleeve is not over-expanded. Additionally, the swellable material must be evenly distributed in the chamber which can be difficult to achieve when using granules or powders.

US2007/0089886 to Schlumberger Technology Corporation discloses an expandable sleeve for use in a well, comprising a tubular structure including an external sealing layer comprising a compliant material; an intermediate expandable tubular body made from a plastically deformable material; and an internal spring structure such as a helically wound spring; wherein the external sealing layer is disposed on the outer surface of the tubular body, and the internal spring structure is disposed inside the tubular body and acts so as to exert a radial force on the body when in an expanded state. In use, the spring must be held in compression when the tubular structure is run-in a well bore and released when the radial support is required. Alternatively, the tubular body is located in the well bore and expanded prior to the spring being run-in and inserted in the expanded to body to provide radial support. A disadvantage of this arrangement is that each of the processes requires a second trip into the well bore to release the spring or locate the spring in position.

GB2417271 to Schlumberger Holdings Limited describes an energised sealing element for a packer that maintains a seal under various conditions by providing a source of stored energy that can be used to insure that contact forces are maintained between the seal and the wall or casing of the wellbore. Various combinations of sealing layers, support sleeves and energising elements are disclosed. The seal layer may be made from rubber, an elastomeric compound, metal, thermoplastic or other soft, deformable materials. The support sleeve and energizing element may be made of metal, composite materials or various other materials that would permit the storage of mechanical potential energy. The energising element may take the form of a bow and wedges, a spring, a bag or container which is energised with gas or other compressible material or a swelling material. For the spring arrangement, a coil type spring is described held in place by a pin or weld. Such an arrangement requires a mechanism to release the spring when the packer is in the desired position. For the bow arrangement, wedges are moved radially inside the bow to force the bow radially outwards to contact and move the support sleeve. Again a mechanism is required to move wedges inside the bow when the packer is to be expanded. Such additional mechanisms may fail, thus preventing expansion of the packer.

It is therefore an object of at least one embodiment of the present invention to provide a morphed isolation barrier which obviates or mitigates one or more disadvantages of the prior art.

It is a further object of at least one embodiment of the present invention to provide a method of creating an isolation barrier in a well bore which obviates or mitigates one or more disadvantages of the prior art.

According to a first aspect of the present invention there is provided an assembly, comprising:

a tubular body arranged to be run in and secured within a larger diameter generally cylindrical structure;

a sleeve member positioned on the exterior of the tubular body, to create a chamber therebetween;

the sleeve member having a first end which is affixed and sealed to the tubular body and a second end which includes a sliding seal to permit longitudinal movement of the second end over the tubular body;

the tubular body including a port to permit the flow of fluid into the chamber to cause the sleeve member to move outwardly and morph against an inner surface of the larger diameter structure; and

characterised in that:

a support frame is located within the chamber;

the frame comprising a plurality of springs supported between a plurality of mounts; and

the frame being compressed by movement of the second end towards the first end as the sleeve member is moved outwardly by fluid pressure and the compressed springs supporting the morphed sleeve member against the inner surface of the larger diameter structure.

In this way, the frame supports the sleeve member to assist in preventing collapse, once the sleeve has been morphed by fluid pressure. The springs are activated by movement of the second end which occurs as part of the morphing process and thus a separate mechanism is not required to actuate the springs.

Preferably, the springs are bow springs, each arranged longitudinally on the frame. In this way, the bow springs are pre-loaded to bend outwards and do not require wedges to force the bow of each spring to move radially outwards.

Preferably, the mounts are annular rings wherein an end of a bow spring is affixed to a respective mount.

Preferably, the plurality of bow springs are spaced circumferentially around the tubular body. In this way, support is provided across the sleeve.

Preferably, the plurality of bow springs are arranged end to end, longitudinally along the tubular body. In this way, the bow spring length does not have to equal the length of the chamber and support can be provided to the sleeve at more than just a central position.

Preferably, the plurality of bow springs are arranged in a staggered configuration around the tubular body. In this way, multiple support points are provided on the sleeve.

To achieve the staggered configuration, one or more bow strings may pass over one or more mounting rings. In this way, an array of support points, each point from a separate bow spring, is created on the inner surface of the sleeve.

Preferably a non-return mechanism is located between the second end of the sleeve member and the tubular body. In this way, the second end can move towards the first end but not away from, so that the frame will remain in a compressed configuration even when the fluid pressure in the chamber drops. In an embodiment, the non-return mechanism is a ratchet as is known in the art.

Alternatively, a non-return mechanism is located between at least one mount and the tubular body. In this way, the support frame can be compressed, but not released so that the frame will remain in a compressed configuration even when the fluid pressure in the chamber drops and the second end moves away from the first end of the sleeve member. In an embodiment, the non-return mechanism is a ratchet as is known in the art.

At least one mount located towards the first end of the sleeve member may be fixed to the tubular body. In this way, the frame does not exert any force against the first end of the sleeve when it is compressed. Alternatively, a stop may be located on the tubular body, in the chamber, towards the first end. In this way, the frame does not exert any force against the first end of the sleeve when it is compressed.

The large diameter structure may be an open hole borehole, a borehole lined with a casing or liner string which may be cemented in place downhole, or may be a pipeline within which another smaller diameter tubular section requires to be secured or centralised.

The tubular body is preferably located coaxially within the sleeve and is part of a tubular string used within a wellbore, run into an open or cased oil, gas or water well. Therefore the present invention allows a casing section or liner to be centralised within a borehole or another downhole underground or above ground pipe by provision of a morphable sleeve member positioned around the casing or liner. Centralisation occurs as the sleeve will expand radially outwardly at a uniform rate with the application of pressure from the fluid. Additionally, the present invention can be used to isolate one section of the downhole annulus from another section of the downhole annulus and thus can also be used to isolate one or more sections of downhole annulus from the production conduit.

Preferably, there is a plurality of ports arranged through the tubular body. In this way, rapid morphing of the sleeve member can be achieved. The ports may be arranged circumferentially around the body. The ports may be arranged longitudinally along the body. As the bow springs are spaced circumferentially around the tubular body, fluid can bypass the springs at all times to act against the sleeve member. This is in contrast to the prior art arrangements of a tube in which slots are cut longitudinally or helically on the tube body. Fluid flow through the wall of the tube is restricted until sufficient longitudinal compression of the tube has occurred to move the strips, between the slots, radially outwards.

The port may include a barrier. In this way, fluid is prevented from entering the chamber until activation is required. The barrier may be a rupture disc which allows fluid to flow through the port at a predetermined fluid pressure. Alternatively the barrier may be a valve. Preferably the valve is a one-way check valve. In this way, fluid is prevented from exiting the chamber. More preferably the valve is set to close when the pressure in the chamber reaches a morphed pressure value. In this way, the support frame is not used to morph the sleeve member, but provides additional support once the sleeve has been morphed.

According to a second aspect of the present invention there is provided a method of setting a morphed sleeve in a well bore, comprising the steps:

-   -   (a) locating a sleeve member on the exterior of a tubular body         and sealing it thereto to create a chamber therebetween,     -   (b) locating a support frame according to the first aspect in         the chamber;     -   (c) running the tubular body on a tubular member into a wellbore         and positioning the sleeve member at a desired location within a         larger diameter structure;     -   (d) pumping fluid through the tubular member and through a port         in the tubular body to access the chamber;     -   (e) causing the sleeve to move radially outwardly and morph         against an inner surface of the larger diameter structure;     -   (f) causing a second end of the sleeve to move longitudinally         over the tubular body towards a first end of the sleeve and         compressing the support frame; and     -   (g) compressing springs of the support frame to contact with and         support the morphed sleeve member.

In this way, the naturally occurring contraction of the sleeve during morphing is used to compress the frame and consequently the springs. Thus no additional actuation is required to create the support.

Preferably, step (g) creates an array of support points, each point from a separate spring, on the inner surface of the sleeve. Preferably, the springs are bow springs.

The large diameter structure may be an open hole borehole, a borehole lined with a casing or liner string which may be cemented in place downhole, or may be a pipeline within which another smaller diameter tubular section requires to be secured or centralised.

Preferably, step (d) includes the step of pumping fluid through the tubular member and through multiple ports in the tubular body to access the chamber. This provides a faster morphing of the sleeve.

Preferably, the method includes the step of rupturing a disc at a valve in the port to allow fluid to enter the chamber when the pressure reaches a desired value. This allows selective and controlled activation of the morphing process.

The method may include the steps of running in an activation fluid delivery tool, creating a temporary seal above and below the port and injecting fluid from the tool into the chamber via the port. Such an arrangement allows selective operation of the sleeve member if more than one sleeve member is arranged in the well bore.

In the description that follows, the drawings are not necessarily to scale. Certain features of the invention may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in the interest of clarity and conciseness. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce the desired results.

Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as “including,” “comprising,” “having,” “containing,” or “involving,” and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term “comprising” is considered synonymous with the terms “including” or “containing” for applicable legal purposes.

All numerical values in this disclosure are understood as being modified by “about”. All singular forms of elements, or any other components described herein including (without limitations) components of the apparatus are understood to include plural forms thereof.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings of which:

FIG. 1 is a cross-sectional view through an assembly according to an embodiment of the present invention;

FIG. 2 is a schematic plan view of a support frame of the assembly of FIG. 1 located in a sleeve;

FIG. 3 is an exploded view of the cross-sectional view of FIG. 1;

FIGS. 4 a-4 c are schematic illustrations of a sequence for setting two sleeve members in an open borehole; FIG. 4 a is a cross-sectional view of a liner provided with two sleeve members; FIG. 4 b shows the liner in the borehole of FIG. 4 a with an activation fluid delivery tool inserted therein; and FIG. 4 c is a cross-sectional view of the liner of FIGS. 4 a and 4 b with morphed sleeves and support frames, in use.

Reference is initially made to FIG. 1 of the drawings which illustrates an assembly, generally indicated by reference numeral 10, including a tubular body 12, sleeve member 14, chamber 16, port 18 and support frame, generally indicated by reference numeral 20, according to an embodiment of the present invention.

Tubular body 12 is a cylindrical tubular section having at a first end 22, a first connector (not shown) and at an opposite end 26, a second connector (not shown) for connecting the body 12 into a tubing string such as casing, liner or production tubing that is intended to be permanently set or completed in a well bore. Body 12 includes a throughbore 30 which is co-linear with the throughbore of the string. The string may be a drill pipe or any other tubular string designed to be run in a well bore.

A port 18 is provided through the side wall 34 of the body 12 to provide a fluid passageway between the throughbore 30 and the outer surface 36 of the body 12. While only a single port 18 is shown, it will be appreciated that a set of ports may be provided. These ports may be equidistantly spaced around the circumference of the body 12 and/or be arranged along the body between the first end 22 and the second end 26 to access the chamber 16.

In an embodiment, at the port 18 there is located a check valve 54. The check valve 54 is a one-way valve which only permits fluid to pass from the throughbore 30 into the chamber 16. The check valve 54 can be made to close when the pressure within the chamber 16 reaches a predetermined level, this being defined as the morphed pressure value. Thus, when the pressure in the sleeve 14 reaches the morphed pressure value, the valve 54 will close. Also arranged at the port 18 is a rupture disc 56. The rupture disc 56 is rated to a desired pressure at which fluid access to the chamber is desired. In this way, the rupture disc 56 can be used to control when the setting of the sleeve 14 is to begin. The disc 56 can be operated by increasing pressure in the throughbore 30 with the pressure to rupture the disc being selected to be greater than the fluid pressure required to activate any other tools or functions in the well bore.

Tubular body 12 is located coaxially within a sleeve member 14. Sleeve member 14 is a steel cylinder being formed from typically 316L or Alloy 28 grade steel but could be any other suitable grade of steel or any other metal material or any other suitable material which undergoes elastic and plastic deformation. Ideally the material exhibits high ductility i.e. high strain before failure. The sleeve member 14 is appreciably thin-walled of lower gauge than the tubing body 12 and is preferably formed from a softer and/or more ductile material than that used for the tool body 12. The sleeve member 14 may be provided with a non-uniform outer surface 40 such as ribbed, grooved or other keyed surface in order to increase the effectiveness of the seal created by the sleeve member 14 when secured within another casing section or borehole.

An elastomer or other deformable material may be bonded to the outer surface 40 of the sleeve 14; this may be as a single coating but is preferably a multiple of bands with gaps therebetween. The bands or coating may have a profile or profiles machined into them. The elastomer bands may be spaced such that when the sleeve 14 is being morphed the bands will contact the inside surface 82 of the open borehole 80 first. The sleeve member 14 will continue to expand outwards into the spaces between the bands, thereby causing a corrugated effect on the sleeve member 14. These corrugations provide a great advantage in that they increase the stiffness of the sleeve member 14, increase its resistance to collapse forces and also improves annular sealing.

A first end 42 of the sleeve 14 is attached to a stop 44 machined in the outer surface 36 of the body 12. Attachment is via pressure-tight connections to provide a seal. An O-ring seal (not shown) may also be provided between the inner surface 46 of the sleeve 14 and the outer surface 36 of the body 12 to act as a secondary seal or backup to the seal provided by the welded connection at the stop 44. Attachment could also be by means of a mechanical clamp.

A second stop 48 is arranged at a second end 50 of the sleeve 14. The second stop 48 may be clamped to the body 12 so that the sleeve 14 can be slid onto the body 12 over the second end during assembly. A seal 52 is provided at the outer surface 36 of the body 12 forward of the stop 48 so that the seal 52 is between the sleeve 14 and the body 12. This provides a sliding seal so that the end of the sleeve 14 is permitted to move towards the first end, relative to the body 12. Thus when the sleeve member 14 is caused to move in the radially outward direction, this causes simultaneous movement of the sliding seal 52, which has the advantage in that the thickness of the sleeve 14 is not further thinned by the radially outwards expansion.

Stop 44 together with the inner surface 46 of the sleeve 14 and the outer surface 36 of the body 12, define a chamber 16. The port 18 is arranged to access the chamber 16 and permit fluid communication between the throughbore 30 and the chamber 16.

Located within the chamber 16 is a support frame 20. Frame 20 comprises an array of mounts 60. Each mount 60 is an annular ring located around the tubular body 12. The inner diameter of each mount 60 is sized to be a clearance fit over the outer surface 36 of the body 12 so that the mounts 60 can move longitudinally with respect to the body 12. The mounts 60 are of a rigid construction, typically a metal which is unaffected by the fluid or the fluid pressure in the chamber 16. The mounts 60 are arranged equidistantly along the length of the chamber 16. Bow springs 62 are arranged between the mounts 60. The bow springs 62 are tensioned metal strips pre-loaded to form a bow in a specific direction when compressed. In a preferred embodiment there are two sets 64,66 of bow springs 62. Referring to FIG. 2, the first set 64 of bow springs 62 comprise four rows 68 a-d of bow springs 62, spaced equidistantly around the circumference of the outer surface 36 of the body 12. Each row 68 a-d has four bow springs 62 a-d arranged end to end to bow in a radially outwards direction from the body 12. A first end 70 a of a bow spring 62 a abuts a second end 72 b of a bow spring 62 b at a mount 60 a. This is best seen in FIG. 3. The ends 70 a, 72 b are fixed in the mount 60 a as they are sandwiched between the mount body 74 and a capping plate 75. Further fixings such as screws may be used to prevent the springs 62 a,b movement with respect to the mount 60 a. The ends 70 b, 70 c, 72 b, 72 c are fixed in the mounts 60 b,c respectively. The first set 64 has three mounts 60 a-c.

The second set 66 of bow springs 62 similarly comprise four rows 68 e-h of bow springs 62, spaced equidistantly around the circumference of the outer surface 36 of the body 12. Each row 68 e-h has three bow springs 62 e-g arranged end to end to bow in a radially outwards direction from the body 12. A first end 70 e of a bow spring 62 e abuts a second end 72 f of a bow spring 62 f at a mount 60 f. The ends 70 e, 72 f and ends 70 f, 72 e are fixed in the mounts 60 f, 60 g, respectively, in the same manner as for the first set 64. The end 72 e of bow spring 62 e is fixed to a first end mount 60 e and the end 70 g of bow spring 62 g is fixed to a second end mount 60 h. The second set 66 has four mounts 60 e-h.

The first set 64 and the second set 66 are interleaved so that the rows 68 a-h of bow springs 62 are spaced equidistantly around the circumference of the outer surface 36 of the body 12, with a row of each set located between rows of the other set. Similarly the mounts 60 of each set 64,66 are arranged alternately along the length of the frame 20. The mounts 60 a-c, 60 e-h are equally spaced with the first end mount 60 e and the second end mount 60 h being at the respective ends of the frame 20.

As the mounts 60 a-c, 60 e-h are interleaved, each bow spring 62 must pass over a mount of the opposite set. This is illustrated in FIG. 3. Bow spring 62 b of the first set 64 is fixed at a first end 70 b to mount 60 b and at a second end 72 b to mount 60 a. Located between the mounts 60 a and 60 b of the first set 64 is mount 60 f of the second set 66. This staggered array of bow springs 62 provides a chequered pattern of multiple contact points between the frame 20 and the inner surface 46 of the sleeve 14. This advantageously provides a distributed even support structure to the sleeve 14.

At a mount 60 a, a ratchet 71 is arranged between the lower surface 73 of the mount 60 a and the outer surface 36 of the body 12. The ratchet 71 is arranged to provide one-way movement of the frame 20 along the surface 36. Movement is permitted which brings the second end 50 of the sleeve 14 towards the first end 44 of the sleeve but not in reverse. In this way, the frame 20 can be compressed by bringing the mounts 60 together as the second end 50 of the sleeve 14 is moved. Compression causes the springs 62 to bow outwards as they reduce in length. The centre of the springs 62 will to push against the inner surface 46 of the sleeve 14. The ratchet 71 holds the frame 20 in a compressed configuration so that the bow springs 62 support the sleeve 14 at the contact points.

Reference will now be made to FIG. 4 of the drawings which provides an illustration of the method for setting a sleeve within a well bore according to an embodiment of the present invention. Like parts to those in the earlier Figures have been given the same reference numerals to aid clarity.

In use, the assembly 10 is conveyed into the borehole by any suitable means, such as incorporating the assembly 10 into a casing or liner string 76 or on an end of a drill pipe and running the string into the wellbore 78 until it reaches the location within the open borehole 80 at which operation of the assembly 10 is intended. This location is normally within the borehole at a position where the sleeve 14 is to be expanded in order to, for example, isolate the section of borehole 80 b located above the sleeve 14 from that below 80 d in order to provide an isolation barrier between the zones 80 b, 80 d. Additionally a further assembly 10 b can be run on the same string 76 so that zonal isolation can be performed in a zone 80 b in order that an injection, frac'ing or stimulation operation can be performed on the formation 80 b located between the two sleeves 14, 14 a. This is as illustrated in FIG. 4B.

Each sleeve 14,14 a can be set by increasing the pump pressure in the throughbore 30 to a predetermined value which ruptures the disc 56 giving fluid access to the chamber 16. Fluid entering the chamber 16 increases in internal volume of the chamber 16, creating a pressure on the inner wall 46 sufficient to cause the sleeve 14 to move radially away from the body 12 by elastic expansion, contact the surface 82 of the borehole and morph to the surface 82 by plastic deformation.

Fluid may be pumped into the chamber 16 at any desired pressure as the the check valve 54 can be set to allow a calculated volume of fluid which is sufficient to morph the sleeve to enter the chamber before closing. When closed, the check-valve will trap any fluid remaining in the chamber 16.

Additionally, by locating a plug at any desired position in the string, such as the bottom of the string, fluid can be pumped from surface or from a tool located in the string to morph any desired number of sleeves, between the surface/tool and the plug, at the same time.

On run-in the frame 20 is in an uncompressed or expanded state. As the sleeve 14 is moved radially outwards, the second end 50 of the sleeve 14 will move towards the first end 42 of the sleeve 14. The sliding seal 52 maintains contact on the liner 76 to ensure the chamber 16 remains sealed. Movement of the second end 50 compresses the frame 20 causing the springs 62 to bow outwards making multiple contact points with the inside wall 46 of the sleeve 14. Note that this movement of the sleeve end 50 does not require separate intervention and occurs automatically on radial movement of the sleeve 14. Likewise, compression of the frame 20 and consequently the bow springs 62 is automatic on morphing of the sleeve 14. As the second end 50 is moved the ratchet 71 prevents expansion of the frame so that the frame 20 and the bow springs 62 will remain in a compressed configuration following morphing of the sleeve 14.

The sleeve 14 will have taken up a fixed shape under plastic deformation with an inner surface 46 matching the profile of the surface 82 of the borehole 80, and an outer surface also matching the profile of the surface 82 to provide a seal which effectively isolates the annulus 84 of the borehole 80 above the sleeve 14 from the annulus 86 below the sleeve 14. If two sleeves 14,14 a are set together then zonal isolation can be achieved for the annulus 84 between the sleeves 14,14 a. At the same time the sleeves 14,14 b have effectively centered, secured and anchored the tubing string 76 to the borehole 80. The bow springs 62 will provide support to the sleeves 14,14 a in the morphed configuration.

An alternative method of achieving morphing of the sleeve 14 is shown in FIG. 4B. This method uses an activation fluid delivery tool 88. Once the string 76 reaches its intended location, tool 88 can be run into the string 76 from surface by means of a coiled tubing 90 or other suitable method. The tool 88 is provided with upper and lower seal means 92, which are operable to radially expand to seal against the inner surface 94 of the body 12 at a pair of spaced apart locations in order to isolate an internal portion of body 12 located between the seals 92; it should be noted that said isolated portion includes the fluid port 18. Tool 88 is also provided with an aperture 96 in fluid communication with the interior of the string 76.

To operate the tool 88, seal means 92 are actuated from the surface to isolate the portion of the tool body 12. Activation fluid is then pumped under pressure through the coiled tubing such that the pressurised fluid flows through tool aperture 96 and then via port 18 into chamber 16 and acts on the swellable material 20 in the same manner as described hereinbefore. Use of such a tool allows setting of selective assemblies 10 in a well bore.

A detailed description of the operation of such a fluid delivery tool 88 is described in GB2398312 in relation to the packer tool 112 shown in FIG. 27 with suitable modifications thereto, where the seal means 92 could be provided by suitably modified seal assemblies 214, 215 of GB2398312, the disclosure of which is incorporated herein by reference. The entire disclosure of GB2398312 is incorporated herein by reference.

Using either pumping method, the increase in pressure of fluid causes the sleeve 14 to move radially outwardly and seal against a portion of the inner circumference of the borehole 80 and the bow springs 62 to be compressed and support the sleeve 14 in the morphed position. The pressure within the chamber 16 continues to increase such that the sleeve 14 initially experiences elastic expansion followed by plastic deformation. The sleeve 14 expands radially outwardly beyond its yield point, undergoing plastic deformation until the sleeve 14 morphs against the surface 82 of the borehole 80 as shown in FIG. 4C. Accordingly, the sleeve 14 has been plastically deformed and morphed by pressure from the chamber contents without any mechanical expansion means being required. Note that the springs 62 support the sleeve during and after morphing of the sleeve but do not contribute to the expansion itself, this being achieved solely by the fluid pressure.

The principle advantage of the present invention is that it provides an assembly for creating an isolation barrier in a well bore in which compressed springs provide support to the morphed sleeve.

A further advantage of the present invention is that it provides a method for setting a sleeve in a well bore in which support of the sleeve is achieved without additional intervention by using movement of the sleeve during the morphing process to compress the springs.

It will be apparent to those skilled in the art that modifications may be made to the invention herein described without departing from the scope thereof. For example, while a plurality of springs is described, a single spring which holds an expanded configuration when compressed could be used. 

1. An assembly, comprising: a tubular body arranged to be run in and secured within a larger diameter generally cylindrical structure; a sleeve member positioned on the exterior of the tubular body, to create a chamber therebetween; the sleeve member having a first end which is affixed and sealed to the tubular body and a second end which includes a sliding seal to permit longitudinal movement of the second end over the tubular body; the tubular body including a port to permit the flow of fluid into the chamber to cause the sleeve member to move outwardly and morph against an inner surface of the larger diameter structure; and characterised in that: a support frame is located within the chamber; the frame comprising a plurality of springs supported between a plurality of mounts; and the frame being compressed by movement of the second end towards the first end as the sleeve member is moved outwardly by fluid pressure and the compressed springs supporting the morphed sleeve member against the inner surface of the larger diameter structure.
 2. An assembly according to claim 1 wherein the springs are bow springs, each arranged longitudinally on the frame.
 3. An assembly according to claim 2 wherein the mounts are annular rings and wherein an end of a bow spring is affixed to a respective mount.
 4. An assembly according to claim 2 wherein the plurality of bow springs are spaced circumferentially around the tubular body.
 5. An assembly according to claim 2 wherein the plurality of bow springs are arranged end to end, longitudinally along the tubular body.
 6. An assembly according to claim 2 wherein the plurality of bow springs are arranged in a staggered configuration around the tubular body.
 7. An assembly according to claim 5 wherein one or more bow strings pass over one or more mounting rings.
 8. An assembly according to claim 1 wherein a non-return mechanism is located between the second end of the sleeve member and the tubular body.
 9. An assembly according to claim 1 wherein a non-return mechanism is located between at least one mount and the tubular body.
 10. An assembly according to claim 8 wherein the non-return mechanism is a ratchet.
 11. An assembly according to claim 1 wherein at least one mount located towards the first end of the sleeve is fixed to the tubular body.
 12. An assembly according to claim 1 wherein a stop is located on the tubular body, in the chamber, towards the first end.
 13. An assembly according to claim 1 wherein the large diameter structure is selected from the group consisting of: an open hole borehole, a borehole lined with a casing or liner string, a borehole lined with a casing or liner string which is cemented in place downhole, a pipeline within which another smaller diameter tubular section requires to be secured or a pipeline within which another smaller diameter tubular section requires to be centralised.
 14. An assembly according to claim 1 wherein the tubular body is located coaxially within the sleeve and is part of a tubular string used within a wellbore.
 15. An assembly according to claim 1 wherein there is a plurality of ports arranged through the tubular body.
 16. A method of setting a morphed sleeve in a well bore, comprising the steps: (a) locating a sleeve member on the exterior of a tubular body and sealing it thereto to create a chamber therebetween, (b) locating a support frame according to the first aspect in the chamber; (c) running the tubular body on a tubular member into a wellbore and positioning the sleeve member at a desired location within a larger diameter structure; (d) pumping fluid through the tubular member and through a port in the tubular body to access the chamber; (e) causing the sleeve to move radially outwardly and morph against an inner surface of the larger diameter structure; (f) causing a second end of the sleeve to move longitudinally over the tubular body towards a first end of the sleeve and compressing the support frame; and (g) compressing springs of the support frame to contact with and support the morphed sleeve member.
 17. A method of setting a morphed sleeve in a well bore according to claim 16 wherein step (g) creates an array of support points, each point from a separate bow spring, on the inner surface of the sleeve.
 18. A method of setting a morphed sleeve in a well bore according to claim 16 wherein step (f) includes the step of moving the second end over a ratchet and preventing the second end from moving away from the first end.
 19. A method of setting a morphed sleeve in a well bore according to claim 16 wherein step (f) includes the step of moving a mount of the support frame over a ratchet on the exterior of the tool body and preventing the mount from moving away from the first end.
 20. A method of setting a morphed sleeve in a well bore according to claim 16 wherein the method includes the steps of running in an activation fluid delivery tool, creating a temporary seal above and below the port and injecting fluid from the tool into the chamber via the port. 